96 DEATH AND RESURRECTION. 



effect we have also been able to explain 

 what happens within matter itself. As 

 it is necessary to understand this in 

 order to comprehend how heat is de- 

 veloped, we will endeavor shortly to 

 outline the present scientific conception 

 of the chemical process called combus- 

 tion. 



From the qualities of matter we have 

 concluded that the bodies we see are 

 composed of extremely tiny particles 

 called molecules, which, however, are 

 so small that with our optical re- 

 sources we never shall be able to ob- 

 serve them. Even the smallest particle 

 of dust visible to the eye must be con- 

 sidered as containing an enormous 

 number of them. With molecules, how- 

 ever, we have not reached the limit 

 of the divisibility of matter. They may 

 themselves be divided by chemical 

 forces into smaller material units 

 called atoms, and these latter are 

 therefore the building stones of which 

 matter is ultimately composed. Now 

 neither the atoms within the molecule, 



